In recent years, a serial differential transfer method has been widely known in the art as a data transfer method between LSIs, in which parallel data is converted to serial data, and the serial data is transferred as a small-amplitude differential signal. In a serial differential transfer method, data can be transferred at a high speed with two terminals, and it is therefore possible not only to reduce the power consumption and the circuit area but also to improve the anti-noise property and suppress the noise generation, thus ensuring a high reliability. With a serial differential transfer method, a clock recovery method can be employed, whereby the clock signal can be incorporated in the data signal. This eliminates the need for a line for transferring the clock signal, thereby reducing the number of cables, and eliminating the need for timing compensation between the clock signal and the data signal, and it is therefore possible to improve the signal quality.
Data transfer systems have been used not only in electric appliances such as TV sets and DVDs, but also in environments where jump-in noise is likely to occur, such as in automobiles. For example, there is a system in which a video signal is transferred from a camera unit for taking an image at the rear of an automobile to a monitor unit installed at the driver's seat, and the image at the rear of the automobile is displayed on the monitor unit, thereby assisting in backing the automobile. Under such circumstances, LSIs may break down due to ESD (Electro-Static Discharge) such as jump-in noise. Therefore, it is preferred that the differential cable and the LSI are AC-coupled together with a capacitor on the substrate wiring so as to prevent LSI breakdown due to ESD and to thus improve the LSI's resistance to a disconnection failure, as disclosed in Japanese Patent No. 3699764 (Patent Document 1), Japanese Patent No. 3419359 (Patent Document 2), Japanese Published Patent Application No. H05-37504 (Patent Document 3).    Patent Document 1: Japanese Patent No. 3699764    Patent Document 2: Japanese Patent No. 3419359    Patent Document 3: Japanese Published Patent Application No. H05-37504